HEIDENHAIN ITNC 530 - PILOT SMART NC Manual page 119

U Positions or point pattern: Define the positions at which the TNC is
to machine the contour pocket (see "Defining Machining Positions" on
page 149)
Specify via soft key for each subcontour whether it is a
pocket or an island.
As a rule, always start the list of subcontours with a pocket
(if required, the deepest pocket)!
On the contour detail form you can define up to a
maximum of nine subcontours.
119